The roles of IL-17A and IL-17F in infection and inflammatory disorders

Abstract

Interleukin-17A (IL-17A) is the signature cytokine of the recently identified T helper 17 (Th17) cell subset. IL-17F shows the highest homology to IL-17A among the IL-17 family and binds to the same IL-17 receptor A (IL-17RA) and IL-17RC receptor complex as IL-17A. Recent studies have demonstrated that IL-17A and IL-17F are also produced by multiple lineages of immune cells, including γδ T cells, NKT cells, and innate lymphoid cells. These cytokines are involved in the development of inflammation, autoimmunity, allergy, and tumors, and also play important roles in host defenses against bacterial and fungal infections. However, it is now clear that IL-17A and IL-17F have overlapping—yet distinct—roles in innate and adoptive immune responses. Here, we describe the recent data on the roles of IL-17A and IL-17F in inflammatory disorders and host defense and discuss the potential of these molecules as therapeutic targets.